1. Field of the Invention
The invention relates to a method for rounding off the edge of a recess on a piston for direct-injection diesel engines.
2. The Prior Art
Such rounded-off recess edges are produced by means of lathe machining of the recess edge at the time the recess is machined by lathe, and serve to prevent tension concentrations. Valve recesses having a base surface that lies at a slant in relation to the piston floor, which intersect with the combustion recess, result in insufficient rounding of the recess edge in the area of the valve recesses. As a solution for the problem of insufficient rounding of the recess edge, it is already known to carry out the recess edge rounding as a so-called S-stroke rounding, see, for example, in DE 4326978, FIGS. 1 and 2. This solution, which is simple in terms of machining, has the disadvantage that the particle emissions increase because of the increased dead volume.